People are now using mobile telephones to download email attachments using their provider networks. Often times the same attachment gets downloaded by multiple people who are part of the same recipient group. There is no standard way to optimize the download and sharing of this same attachment (or set of attachments). What is needed is a way to recognize this download redundancy and to optimize it to reduce the data usage for mobile telephone users. In the increasingly interconnected world where smart phones are used as a tool for social media, entertainment and office work, the data usage of a phone needs to be optimized to save cost and bandwidth for corporations and users.